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What's That Space Rock?

The path through the solar system is a rocky road. Asteroids, comets, Kuiper Belt Objects—all kinds of small bodies of rock, metal and ice are in constant motion as they orbit the Sun. But what’s the difference between them, anyway? And why do these miniature worlds fascinate space explorers so much? The answer is profound: they may hold the keys to better understanding where we all come from. Here’s 10 things to know about the solar system this week:

This picture of Eros, the first of an asteroid taken from an orbiting spacecraft, came from our NEAR mission in February 2000. Image credit: NASA/JPL

1. Asteroids

Asteroids are rocky, airless worlds that orbit our Sun. They are remnants left over from the formation of our solar system, ranging in size from the length of a car to about as wide as a large city. Asteroids are diverse in composition; some are metallic while others are rich in carbon, giving them a coal-black color. They can be “rubble piles,” loosely held together by their own gravity, or they can be solid rocks.

Most of the asteroids in our solar system reside in a region called the main asteroid belt. This vast, doughnut-shaped ring between the orbits of Mars and Jupiter contains hundreds of thousands of asteroids, maybe millions. But despite what you see in the movies, there is still a great deal of space between each asteroid. With all due respect to C3PO, the odds of flying through the asteroid belt without colliding with one are actually pretty good.

Other asteroids (and comets) follow different orbits, including some that enter Earth’s neighborhood. These are called near-Earth objects, or NEOs. We can actually keep track of the ones we have discovered and predict where they are headed. The Minor Planet Center (MPC) and Jet Propulsion Laboratory’s Center for Near Earth Object Studies (CNEOS) do that very thing. Telescopes around the world and in space are used to spot new asteroids and comets, and the MPC and CNEOS, along with international colleagues, calculate where those asteroids and comets are going and determine whether they might pose any impact threat to Earth.

For scientists, asteroids play the role of time capsules from the early solar system, having been preserved in the vacuum of space for billions of years. What’s more, the main asteroid belt may have been a source of water—and organic compounds critical to life—for the inner planets like Earth.

The nucleus of Comet 67P/Churyumov-Gerasimenko, as seen in January 2015 by the European Space Agency’s Rosetta spacecraft. Image credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

2. Comets

Comets also orbit the Sun, but they are more like snowballs than space rocks. Each comet has a center called a nucleus that contains icy chunks of frozen gases, along with bits of rock and dust. When a comet’s orbit brings it close to the Sun, the comet heats up and spews dust and gases, forming a giant, glowing ball called a coma around its nucleus, along with two tails – one made of dust and the other of excited gas (ions). Driven by a constant flow of particles from the Sun called the solar wind, the tails point away from the Sun, sometimes stretching for millions of miles.

While there are likely billions of comets in the solar system, the current confirmed number is 3,535. Like asteroids, comets are leftover material from the formation of our solar system around 4.6 billion years ago, and they preserve secrets from the earliest days of the Sun’s family. Some of Earth’s water and other chemical constituents could have been delivered by comet impacts.

An artist re-creation of a collision in deep space. Image credit: NASA/JPL-Caltech

3. Meteoroids

Meteoroids are fragments and debris in space resulting from collisions among asteroids, comets, moons and planets. They are among the smallest “space rocks.” However, we can actually see them when they streak through our atmosphere in the form of meteors and meteor showers.

This photograph, taken by an astronaut aboard the International Space Station, provides the unusual perspective of looking down on a meteor as it passes through the atmosphere. The image was taken on Aug. 13, 2011, during the Perseid meteor shower that occurs every August. Image credit: NASA

4. Meteors

Meteors are meteoroids that fall through Earth’s atmosphere at extremely high speeds. The pressure and heat they generate as they push through the air causes them to glow and create a streak of light in the sky. Most burn up completely before touching the ground. We often refer to them as “shooting stars.” Meteors may be made mostly of rock, metal or a combination of the two.

Scientists estimate that about 48.5 tons (44,000 kilograms) of meteoritic material falls on Earth each day.

The constellation Orion is framed by two meteors during the Perseid shower on Aug. 12, 2018 in Cedar Breaks National Monument, Utah. Image credit: NASA/Bill Dunford

5. Meteor Showers

Several meteors per hour can usually be seen on any given night. Sometimes the number increases dramatically—these events are termed meteor showers. They occur when Earth passes through trails of particles left by comets. When the particles enter Earth’s atmosphere, they burn up, creating hundreds or even thousands of bright streaks in the sky. We can easily plan when to watch meteor showers because numerous showers happen annually as Earth’s orbit takes it through the same patches of comet debris. This year’s Orionid meteor shower peaks on Oct. 21.

An SUV-sized asteroid, 2008TC#, impacted on Oct. 7, 2008, in the Nubian Desert, Northern Sudan. Dr. Peter Jenniskens, NASA/SETI, joined Muawia Shaddas of the University of Khartoum in leading an expedition on a search for samples. Image credit: NASA/SETI/P. Jenniskens

6. Meteorites

Meteorites are asteroid, comet, moon and planet fragments (meteoroids) that survive the heated journey through Earth’s atmosphere all the way to the ground. Most meteorites found on Earth are pebble to fist size, but some are larger than a building.

Early Earth experienced many large meteorite impacts that caused extensive destruction. Well-documented stories of modern meteorite-caused injury or death are rare. In the first known case of an extraterrestrial object to have injured a human being in the U.S., Ann Hodges of Sylacauga, Alabama, was severely bruised by a 8-pound (3.6-kilogram) stony meteorite that crashed through her roof in November 1954.

The largest object in the asteroid belt is actually a dwarf planet, Ceres. This view comes from our Dawn mission. The color is approximately as it would appear to the eye. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

7. Dwarf Planets

Don’t let the name fool you; despite their small size, dwarf planets are worlds that are just as compelling as their larger siblings. Dwarf planets are defined by astronomers as bodies massive enough to be shaped by gravity into a round or nearly round shape, but they don’t have enough of their own gravitational muscle to clear their path of other objects as they orbit the Sun. In our solar system, dwarf planets are mostly found in the Kuiper Belt beyond Neptune; Pluto is the best-known example. But the largest object in the asteroid belt is the dwarf planet Ceres. Like Pluto, Ceres shows signs of active geology, including ice volcanoes.

8. Kuiper Belt Objects

The Kuiper Belt is a disc-shaped region beyond Neptune that extends from about 30 to 55 astronomical units – that is, 30 to 55 times the distance from the Earth to the Sun. There may be hundreds of thousands of icy bodies and a trillion or more comets in this distant region of our solar system.

An artist’s rendition of the New Horizons spacecraft passing by the Kuiper Belt Object MU69 in January 2019. Image credits: NASA/JHUAPL/SwRI

Besides Pluto, some of the mysterious worlds of the Kuiper Belt include Eris, Sedna, Quaoar, Makemake and Haumea. Like asteroids and comets, Kuiper Belt objects are time capsules, perhaps kept even more pristine in their icy realm.

This chart puts solar system distances in perspective. The scale bar is in astronomical units (AU), with each set distance beyond 1 AU representing 10 times the previous distance. One AU is the distance from the Sun to the Earth, which is about 93 million miles or 150 million kilometers. Neptune, the most distant planet from the Sun, is about 30 AU. Image credit: NASA/JPL-Caltech

9. Oort Cloud Objects

The Oort Cloud is a group of icy bodies beginning roughly 186 billion miles (300 billion kilometers) away from the Sun. While the planets of our solar system orbit in a flat plane, the Oort Cloud is believed to be a giant spherical shell surrounding the Sun, planets and Kuiper Belt Objects. It is like a big, thick bubble around our solar system. The Oort Cloud’s icy bodies can be as large as mountains, and sometimes larger.

This dark, cold expanse is by far the solar system’s largest and most distant region. It extends all the way to about 100,000 AU (100,000 times the distance between Earth and the Sun) – a good portion of the way to the next star system. Comets from the Oort Cloud can have orbital periods of thousands or even millions of years. Consider this: At its current speed of about a million miles a day, our Voyager 1 spacecraft won’t reach the Oort Cloud for more than 300 years. It will then take about 30,000 years for the spacecraft to traverse the Oort Cloud, and exit our solar system entirely.

This animation shows our OSIRIS-REx spacecraft collecting a sample of the asteroid Bennu, which it is expected to do in 2020. Image credit: NASA/Goddard Space Flight Center

10. The Explorers

Fortunately, even though the Oort Cloud is extremely distant, most of the small bodies we’ve been discussing are more within reach. In fact, NASA and other space agencies have a whole flotilla of robotic spacecraft that are exploring these small worlds up close. Our mechanical emissaries act as our eyes and hands in deep space, searching for whatever clues these time capsules hold.

A partial roster of our current or recent missions to small, rocky destinations includes:

OSIRIS-REx – Now approaching the asteroid Bennu, where it will retrieve a sample in 2020 and return it to the Earth for close scrutiny.

New Horizons – Set to fly close to MU69 or “Ultima Thule,” an object a billion miles past Pluto in the Kuiper Belt on Jan. 1, 2019. When it does, MU69 will become the most distant object humans have ever seen up close.

Psyche – Planned for launch in 2022, the spacecraft will explore a metallic asteroid of the same name, which may be the ejected core of a baby planet that was destroyed long ago.

Lucy – Slated to investigate two separate groups of asteroids, called Trojans, that share the orbit of Jupiter – one group orbits ahead of the planet, while the other orbits behind. Lucy is planned to launch in 2021.

Dawn – Finishing up a successful seven-year mission orbiting planet-like worlds Ceres and Vesta in the asteroid belt.

Plus these missions from other space agencies:

The Japan Aerospace Exploration Agency (JAXA)’s Hayabusa2– Just landed a series of small probes on the surface of the asteroid Ryugu.

The European Space Agency (ESA)’s Rosetta – Orbited the comet 67P/Churyumov-Gerasimenko and dispatched a lander to its surface.

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Você acha que a única beleza de Saturno é o seu sistema de anéis? A atmosfera também é um show a parte!!!

Pôr da Lua no Pôr do Sol! 🌙☀️

📅 Data de registro: 5 de agosto de 2024 às 18:23

E a descoberta de exoplanetas continua, bem, isso é meio óbvio, aliás, é uma das áreas mais prolíficas da astronomia atualmente em grandes descobertas.

Dessa vez uma equipe internacional de astrônomos detectou 3 exoplanetas num sistema estelar binário formado por estrelas gêmeas.

O sistema estelar HD 133131 está localizado a aproximadamente 163 anos-luz de distância da Terra, é um sistema binário que foi descoberto em 1972, tem uma idade estimada de 9.5 bilhões de anos e é formado por duas estrelas gêmeas, ou seja, de mesmo tipo espectral, e que são também do mesmo tipo espectral que o Sol, G2V.

As estrelas estão separadas por 360 UA.

Tudo isso faz desse sistema, primeiro, o formado por estrelas mais próximas onde foram descobertos exoplanetas, e além disso, ambas as estrelas do sistema possuem planetas.

Uma das estrelas possui dois planetas com massas 0.6 e 1.4 vezes a massa de Júpiter e a outra estrela possui um planetas com uma massa 2.5 vezes a massa de Júpiter, ou seja, todos são planetas gigantes.

Mas esse sistema possui mais características peculiares.

As estrelas desse sistema são classificadas como sendo pobres em metal, ou seja, são formadas principalmente por hidrogênio e hélio, isso é incomum em estrelas que abrigam planetas gigantes, já que a maioria é rica em metal e somente 6 sistemas binários pobres em metal foram encontrados com exoplanetas, o que deixa a descoberta mais intrigante.

Já não bastasse tudo isso, ao estudar o sistema em detalhe, os astrônomos descobriram que as estrelas na verdade, possuem uma pequena diferença química na sua composição, o que deixaria de fazer com que elas fossem gêmeas idênticas, e passassem então a serem classificadas somente como gêmeas.

Essa diferenciação pode indicar que uma estrela pode ter engolido planetas menores ainda em formação e isso alterou sua composição química, levemente.

Essa descoberta marcou também a primeira descoberta feita somente com dados obtidos pelo instrumento Planet Finder Spectrograph, que fica acoplado ao Telescópio Magellan II de 6.5 metros no Observatório de Las Campanas no Chile.

Descobrir um sistema tão único assim é de suma importância para se entender a formação de planetas especialmente em sistemas binários.

Ajudar a montar o quebra cabeça de como o Sistema Solar se formou e de alguma forma ajudar os astrônomos a compreender onde planetas possivelmente habitáveis poderiam ser encontrados.

(via https://www.youtube.com/watch?v=GHMfsc0BFj4)

Hoje vamos falar um pouco de Urano.

Urano, as vezes é considerado como o paneta esquecido do nosso Sistema Solar, ele está muito longe, foi visitado só uma vez por uma sonda em 1986, pela Voyager II.

Urano é o sétimo planeta em distância do Sol, e o terceiro maior em tamanho, perdendo somente para Júptier e Saturno.

Urano possuem finos anéis de poeira e um conjunto incrível de 27 luas que nós conhecemos até hoje.

Na verdade é um pouco ridículo não termos tanto interesse assim, nesse grande planeta do nosso Sistema Solar.

Para vocês terem uma ideia, sabemos mais de Plutão e temos imagens mais detalhadas de Plutão do que de Urano.

Talvez o aspecto mais estranho de Urano seja a sua inclinação. Ele praticamente gira deitado.

Na verdade todos os planetas do Sistema Solar têm uma inclinação, a da Terra é de 23.5 graus, de Marte, 25 graus, e até Mercúrio tem uma inclinação de 2.1 graus.

Agora Urano, tem uma inclinação do eixo de rotação de 97.8 graus.

A grande questão então é, o que teria acontecido com Urano, para ter uma inclinação tão grande assim?

Para entender isso, teremos que voltar no início da história do Sistema Solar. A nossa vizinhança era um lugar bem violento e não muito amigável de se viver.

Muitas colisões aconteciam, entre corpos gigantescos, colisões catastróficas, vide a colisão da Terra com um corpo quase do tamanho de Marte que gerou a nossa Lua.

As colisões eram tão violentas, que os planetas mudavam de órbita, outros eram expulsos do Sistema Solar e outros mergulhavam diretamente na direção do Sol.

Com Urano, certamente aconteceu isso, uma colisão violenta que fez com que ele se inclinasse, e essa colisão aconteceu quando ele ainda estava circundado pelo disco de poeira que deu origem às suas luas, e nós sabemos disso, pois as luas orbitam Urano na mesma inclinação do seu eixo de rotação.

Os astrônomos atualmente acreditam que não foi uma única colisão que fez isso com Urano, mas sim uma série de colisões. Se fosse uma só, Urano giraria diferente, com uma série de colisões, elas agem como freios, colocando o planta na rotação correta.

Qual a consequência disso? Bem, imagine você na superfície de Urano (tudo bem, ele não tem superfície é uma bola de gás, mas imagine que tem), se você estivesse no polo você veria o Sol acima do horizonte por 42 anos, fazendo círculos cada vez maiores até desaparecer no horizonte, e depois ficaria 42 anos sem ver o Sol.

O Sistema Solar é feito de sobreviventes, e a nossa Terra, um sobrevivente mais sortudo ainda. Mas olhando para os outros planetas podemos ver que a vida realmente não foi fácil no início da história do Sistema Solar.

(via https://www.youtube.com/watch?v=Nk_hBs2Ci48)

Pegue carona nessa cauda de cometa! !! Cometa Lovejoy fotografado pelos astronautas da Expedição 30 na ISS

Gardner Megadome (também conhecido como Vitruvius T1):

Grande escudo vulcânico.

Diâmetro: 70 Km;

Altitude máxima: 1,6 Km;

Coordenadas Selenográficas: LAT: 16º 44’ 00’ N, LON: 33º 56’ 00” E;

Período Geológico Lunar: Não determinado.

Melhor período para observação: cinco dias após a Lua nova ou quatro dias após a Lua cheia. Quem foi GARDNER? Dr. Irvine Clifton Gardner (1889-1972) foi um físico americano que em 1921 se juntou ao National Bureau of Standards e em 1950 tornou-se chefe da Divisão de Óptica e Meteorologia. Ele foi presidente da Optical Society of America em 1958. Ficou conhecido por seu trabalho em óptica e no campo da espectroscopia.

Gardner Megadome foi, provavelmente, um imenso vulcão lunar, com 70 Km de diâmetro e 1,6 Km de altitude máxima, caracterizado como um grande escudo vulcânico, de textura áspera, formado possivelmente por um complexo coeso de domos sobrepostos e cobertos por lava, apresentando muitos impactos de minúsculas crateras em sua superfície.

Gardner Megadome é uma formação incomum, que consiste numa enorme área elevada localizada logo ao sul da cratera GARDNER (diâmetro: 18 Km, profundidade: 3,0 Km), com uma grande depressão no topo com indícios e possibilidades de ser uma caldeira vulcânica, conhecida como cratera Vitruvius H (diâmetro: 22 Km, profundidade: 400 m).

A cratera VITRUVIUS (diâmetro:29 Km, profundidade: 1,9 Km) localiza-se logo a noroeste do interessante Gardner Megadome.

Foto executada por Vaz Tolentino com apenas 1 frame em 10‎ de ‎abril‎ de ‎2012, ‏‎04:07:54 (07:07:54 UT).

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Flying to New Heights With the Magnetospheric Multiscale Mission

A mission studying Earth’s magnetic field by flying four identical spacecraft is headed into new territory. 

The Magnetospheric Multiscale mission, or MMS, has been studying the magnetic field on the side of Earth facing the sun, the day side – but now we’re focusing on something else. On February 9, MMS started the three-month-long process of shifting to a new orbit. 

One key thing MMS studies is magnetic reconnection – a process that occurs when magnetic fields collide and re-align explosively into new positions. The new orbit will allow MMS to study reconnection on the night side of the Earth, farther from the sun.

Magnetic reconnection on the night side of Earth is thought to be responsible for causing the northern and southern lights.  

To study the interesting regions of Earth’s magnetic field on the night side, the four MMS spacecraft are being boosted into an orbit that takes them farther from Earth than ever before. Once it reaches its final orbit, MMS will shatter its previous Guinness World Record for highest altitude fix of a GPS.

To save on fuel, the orbit is slowly adjusted over many weeks. The boost to take each spacecraft to its final orbit will happen during the first week of April.

On April 19, each spacecraft will be boosted again to raise its closest approach to Earth, called perigee. Without this step, the spacecraft would be way too close for comfort – and would actually reenter Earth’s atmosphere next winter! 

The four MMS spacecraft usually fly really close together – only four miles between them – in a special pyramid formation called a tetrahedral, which allows us to examine the magnetic environment in three dimensions.

But during orbit adjustments, the pyramid shape is broken up to make sure the spacecraft have plenty of room to maneuver. Once MMS reaches its new orbit in May, the spacecraft will be realigned into their tetrahedral formation and ready to do more 3D magnetic science.

Learn more about MMS and find out what it’s like to fly a spacecraft.

Let History Never Forget the Name Enterprise

Just as the captains of the fictional 24th century Starfleet blazed a trail among the stars, the space shuttle Enterprise helped pave the way for future space exploration. 

Fifty years ago, Star Trek debuted with the USS Enterprise as the main space-faring vessel used in much of the Star Trek universe. As such, the vessel holds a treasured place in the hearts of Star Trek fans and is as much of a character in the show as Kirk and Spock. Over three different series and a total of 14 seasons on TV and 13 feature films, the iterations of Enterprise have captured the imaginations and provided inspiration for its fans across the globe. 

This brief history of the shuttle tells the tale of humanity’s first reusable spacecraft. Space shuttles were first built in the late 1970s and were flown in space from 1981 to 2011. Their missions ranged from helping to build the International Space Station to repairing the Hubble Space Telescope.   

It’s All In The Name

The first shuttle was originally to be named Constitution, celebrating the country’s bicentennial and was to be unveiled to the public on Constitution Day, Sept. 17, 1976. However, a massive letter-writing campaign by Star Trek fans prompted President Gerald Ford to suggest the change. In the above photo, we see the shuttle Enterprise rolled out in Palmdale, California, with cast members of Star Trek on Sept. 17, 1976. 

To Boldly Go …

This circular red, white and blue emblem was  the official insignia for the Space Shuttle Approach and Landing Test flights and became a model for future space shuttle mission patch designs, including placing the names of the crew on the patch . The four astronauts listed on the patch are: 

Fred Haise., commander of the first crew 

Charles Fullerton, pilot of the first crew 

Joe Engle, commander of the second crew 

Dick Truly, pilot of the second crew 

First Impressions

In this image, Enterprise makes its first appearance mated to its boosters as it is slowly rolled to the huge Vehicle Assembly Building (VAB) at Kennedy Space Center. Although she never flew in space, shuttle Enterprise underwent a series of fit and function checks on the pad in preparation for the first launch of its sister craft, Columbia.

Not Meant To Be

Enterprise sits on Launch Complex 39 at Kennedy Space Center undergoing tests after completing its 3.5 mile journey from the VAB. Have you ever wondered why Enterprise never went into space? Converting Enterprise from a training vehicle to space-worthy one was too cost prohibitive, our engineers felt.

Engage

Commander Fred Haise and pilot Charles Fullerton are seen in the cockpit of Enterprise prior to the fifth and final Approach and Landing Test at Dryden Flight Research Center (Armstrong Flight Research Center). The tests were performed to learn about the landing characteristics of the shuttle.

It’s Been An Honor To Serve With You

The Enterprise’s two crews pose for a photo op at the Rockwell International Space Division’s Orbiter assembly facility at Palmdale, California. They are (left to right) Charles Fullerton, Fred Haise, Joe Engle and Dick Truly.

Fair Winds And Following Seas

On July 6, 2012, the Enterprise, atop a barge, passes the Statue of Liberty on its way to the Intrepid Sea, Air and Space Museum, where is now permanently on display.

Learn more about Star Trek and NASA.

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Feliz Natal! 🤩⛪✝️